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/*****************************************************************************
* aout_sdl.c : audio sdl functions library
*****************************************************************************
* Copyright (C) 1999, 2000 VideoLAN
* $Id: aout_sdl.c,v 1.12 2001/04/28 03:36:25 sam Exp $
*
* Authors: Michel Kaempf <maxx@via.ecp.fr>
* Samuel Hocevar <sam@zoy.org>
* Pierre Baillet <oct@zoy.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
*****************************************************************************/
#define MODULE_NAME sdl
#include "modules_inner.h"
/*****************************************************************************
* Preamble
*****************************************************************************/
#include "defs.h"
#include <errno.h> /* ENOMEM */
#include <fcntl.h> /* open(), O_WRONLY */
#include <string.h> /* strerror() */
#include <unistd.h> /* write(), close() */
#include <stdio.h> /* "intf_msg.h" */
#include <stdlib.h> /* calloc(), malloc(), free() */
#include <SDL/SDL.h> /* SDL base include */
#include "config.h"
#include "common.h" /* boolean_t, byte_t */
#include "threads.h"
#include "mtime.h"
#include "tests.h"
#include "audio_output.h" /* aout_thread_t */
#include "intf_msg.h" /* intf_DbgMsg(), intf_ErrMsg() */
#include "main.h"
#include "modules.h"
/*****************************************************************************
* aout_sys_t: dsp audio output method descriptor
*****************************************************************************
* This structure is part of the audio output thread descriptor.
* It describes the dsp specific properties of an audio device.
*****************************************************************************/
/* the overflow limit is used to prevent the fifo from growing too big */
#define OVERFLOWLIMIT 100000
typedef struct aout_sys_s
{
byte_t * audio_buf;
int i_audio_end;
boolean_t b_active;
} aout_sys_t;
/*****************************************************************************
* Local prototypes.
*****************************************************************************/
static int aout_Probe ( probedata_t *p_data );
static int aout_Open ( aout_thread_t *p_aout );
static int aout_SetFormat ( aout_thread_t *p_aout );
static long aout_GetBufInfo ( aout_thread_t *p_aout, long l_buffer_info );
static void aout_Play ( aout_thread_t *p_aout,
byte_t *buffer, int i_size );
static void aout_Close ( aout_thread_t *p_aout );
static void aout_SDLCallback ( void *userdata, Uint8 *stream, int len );
/*****************************************************************************
* Functions exported as capabilities. They are declared as static so that
* we don't pollute the namespace too much.
*****************************************************************************/
void _M( aout_getfunctions )( function_list_t * p_function_list )
{
p_function_list->pf_probe = aout_Probe;
p_function_list->functions.aout.pf_open = aout_Open;
p_function_list->functions.aout.pf_setformat = aout_SetFormat;
p_function_list->functions.aout.pf_getbufinfo = aout_GetBufInfo;
p_function_list->functions.aout.pf_play = aout_Play;
p_function_list->functions.aout.pf_close = aout_Close;
}
/*****************************************************************************
* aout_Probe: probe the audio device and return a score
*****************************************************************************
* This function tries to initialize SDL audio and returns a score to the
* plugin manager so that it can select the best plugin.
*****************************************************************************/
static int aout_Probe( probedata_t *p_data )
{
SDL_AudioSpec desired, obtained;
/* Start AudioSDL */
if( SDL_Init(SDL_INIT_AUDIO | SDL_INIT_NOPARACHUTE) != 0 )
{
intf_DbgMsg( "aout: SDL_Init failed (%s)", SDL_GetError() );
return( 0 );
}
desired.freq = 11025; /* frequency */
desired.format = AUDIO_U8; /* unsigned 8 bits */
desired.channels = 2; /* mono */
desired.callback = aout_SDLCallback; /* callback function mandatory */
desired.userdata = NULL; /* null parm for callback */
desired.samples = 4096;
/* If we were unable to open the device, there is no way we can use
* the plugin. Return a score of 0. */
if( SDL_OpenAudio( &desired, &obtained ) < 0 )
{
intf_DbgMsg( "aout: SDL_OpenAudio failed (%s)", SDL_GetError() );
return( 0 );
}
/* Otherwise, there are good chances we can use this plugin, return 100. */
intf_DbgMsg( "aout: SDL_OpenAudio successfully run" );
SDL_CloseAudio();
if( TestMethod( AOUT_METHOD_VAR, "sdl" ) )
{
return( 999 );
}
return( 40 );
}
/*****************************************************************************
* aout_Open: open the audio device
*****************************************************************************
* This function opens the dsp as a usual non-blocking write-only file, and
* modifies the p_aout->i_fd with the file's descriptor.
*****************************************************************************/
static int aout_Open( aout_thread_t *p_aout )
{
SDL_AudioSpec desired;
int i_channels = p_aout->b_stereo ? 2 : 1;
/* Allocate structure */
p_aout->p_sys = malloc( sizeof( aout_sys_t ) );
if( p_aout->p_sys == NULL )
{
intf_ErrMsg( "aout error: %s", strerror(ENOMEM) );
return( 1 );
}
p_aout->p_sys->i_audio_end = 0;
p_aout->p_sys->audio_buf = malloc( OVERFLOWLIMIT );
/* Initialize some variables */
p_aout->psz_device = 0;
p_aout->i_format = AOUT_FORMAT_DEFAULT;
p_aout->i_channels = 1 + main_GetIntVariable( AOUT_STEREO_VAR,
AOUT_STEREO_DEFAULT );
p_aout->l_rate = main_GetIntVariable( AOUT_RATE_VAR,
AOUT_RATE_DEFAULT );
desired.freq = p_aout->l_rate;
/* TODO: write conversion beetween AOUT_FORMAT_DEFAULT
* AND AUDIO* from SDL. */
desired.format = AUDIO_S16LSB; /* stereo 16 bits */
desired.channels = i_channels;
desired.callback = aout_SDLCallback;
desired.userdata = p_aout->p_sys;
desired.samples = 1024;
/* Open the sound device
* we just ask the SDL to wrap at the good frequency if the one we
* ask for is unavailable. This is done by setting the second parar
* to NULL
*/
if( SDL_OpenAudio( &desired, NULL ) < 0 )
{
intf_ErrMsg( "aout error: SDL_OpenAudio failed (%s)", SDL_GetError() );
return( -1 );
}
p_aout->p_sys->b_active = 1;
SDL_PauseAudio( 0 );
return( 0 );
}
/*****************************************************************************
* aout_SetFormat: reset the audio device and sets its format
*****************************************************************************
* This functions resets the audio device, tries to initialize the output
* format with the value contained in the dsp structure, and if this value
* could not be set, the default value returned by ioctl is set. It then
* does the same for the stereo mode, and for the output rate.
*****************************************************************************/
static int aout_SetFormat( aout_thread_t *p_aout )
{
/* TODO: finish and clean this */
SDL_AudioSpec desired;
int i_stereo = p_aout->b_stereo ? 2 : 1;
/*i_format = p_aout->i_format;*/
desired.freq = p_aout->l_rate; /* Set the output rate */
desired.format = AUDIO_S16LSB; /* stereo 16 bits */
desired.channels = i_stereo;
desired.callback = aout_SDLCallback;
desired.userdata = p_aout->p_sys;
desired.samples = 2048;
/* Open the sound device */
SDL_PauseAudio( 1 );
SDL_CloseAudio();
if( SDL_OpenAudio( &desired, NULL ) < 0 )
{
p_aout->p_sys->b_active = 0;
return( -1 );
}
p_aout->p_sys->b_active = 1;
SDL_PauseAudio( 0 );
return( 0 );
}
/*****************************************************************************
* aout_GetBufInfo: buffer status query
*****************************************************************************
* returns the number of bytes in the audio buffer compared to the size of
* l_buffer_limit...
*****************************************************************************/
static long aout_GetBufInfo( aout_thread_t *p_aout, long l_buffer_limit )
{
if(l_buffer_limit > p_aout->p_sys->i_audio_end)
{
/* returning 0 here juste gives awful sound in the speakers :/ */
return( l_buffer_limit );
}
return( p_aout->p_sys->i_audio_end - l_buffer_limit);
}
/*****************************************************************************
* aout_Play: play a sound samples buffer
*****************************************************************************
* This function writes a buffer of i_length bytes in the dsp
*****************************************************************************/
static void aout_Play( aout_thread_t *p_aout, byte_t *buffer, int i_size )
{
byte_t * audio_buf = p_aout->p_sys->audio_buf;
SDL_LockAudio(); /* Stop callbacking */
p_aout->p_sys->audio_buf = realloc( audio_buf,
p_aout->p_sys->i_audio_end + i_size);
memcpy( p_aout->p_sys->audio_buf + p_aout->p_sys->i_audio_end,
buffer, i_size);
p_aout->p_sys->i_audio_end += i_size;
SDL_UnlockAudio(); /* go on callbacking */
}
/*****************************************************************************
* aout_Close: close the audio device
*****************************************************************************/
static void aout_Close( aout_thread_t *p_aout )
{
if( p_aout->p_sys->b_active )
{
SDL_PauseAudio( 1 ); /* pause audio */
if( p_aout->p_sys->audio_buf != NULL ) /* do we have a buffer now ? */
{
free( p_aout->p_sys->audio_buf );
}
}
SDL_CloseAudio();
free( p_aout->p_sys ); /* Close the Output. */
}
/*****************************************************************************
* aout_SDLCallback: what to do once SDL has played sound samples
*****************************************************************************/
static void aout_SDLCallback( void *userdata, byte_t *stream, int len )
{
struct aout_sys_s * p_sys = userdata;
if( p_sys->i_audio_end > OVERFLOWLIMIT )
{
intf_ErrMsg( "aout error: aout_SDLCallback overflowed" );
free( p_sys->audio_buf );
p_sys->audio_buf = NULL;
p_sys->i_audio_end = 0;
/* we've gone to slow, increase output freq */
}
/* if we are not in underrun */
if( p_sys->i_audio_end > len )
{
p_sys->i_audio_end -= len;
memcpy( stream, p_sys->audio_buf, len );
memmove( p_sys->audio_buf, p_sys->audio_buf + len, p_sys->i_audio_end );
}
}